By the time you build a basic phone, adding these features only costs a few cents more, so they include them to increase market share.

These days phones are generally built from a SoC which already includes more capabilities than just calls and text, and run an operating system which already supports those capabilities.

If you don’t want certain features they can be turned off (check how locked down you can make an iPhone via parental controls, for instance) but it’s hard to avoid paying for them in some way.